Cyanuric chloride which is recovered by trimerization of cyanogen chloride with the help of catalyst, above all activated carbon, as is known is a very interesting intermediate product for various industrial sectors such as the production of dyestuffs and products for the textile industry, as well as for pharmaceuticals, products for agriculture as well as for the synthetic resin, rubber and explosives industries.
As is known after the trimerization cyanuric chloride is obtained in gaseous form together with unreacted cyanogen chloride and chlorine as well as byproducts.
For a long time, it was customary to convert this gaseous reaction mixture directly into solid cyanuric chloride, e.g., by conducting the gaseous mixture into a chamber cooled from the outside (see Ullmann, Enzyklopadie der technischen Chemie, 3rd Edition, 1954, Volume 5, pages 624-625 and 4th Edition, 1975, Volume 9, page 652).
It has also been passed into a ball mill cooled with water according to the process of Trickey U.S. Pat. No. 3,256,070.
Solid cyanuric chloride generally is obtained in powdery form and until now was predominantly further processed in this form.
A disadvantage of the solid cyanuric chloride, however, is that it is frequently not simple to handle.
In the recovery of solid cyanuric chloride by direct desublimation of the reaction gases in separation chambers it was a disadvantage that it was difficult to produce fine-grained products with a narrow grain spectrum.
Thus a part of the cyanuric chloride frequently deposited in the form of coarse crystals on the walls and installations of the desublimation chambers which then had to be mechanically knocked off and had to be reduced to the smaller grain diameter in a subsequent step, entirely apart from the interruption in operating required thereby.
The net result was that residues of chlorine and cyanogen chloride were still enclosed in the final product as a result of which not only caking occurred but also the storage and further processing of the cyanuric chloride was made more difficult.
Furthermore because of corrosive reaction gas constituents chlorine and cyanogen chloride there is also the danger of corrosions in the separatory and discharge aggregates.
Therefore there were endeavors to find other ways for the recovery of cyanuric chloride from the reaction gases.
Thus there are processes known in which the cyanuric chloride contained in the reaction gas is liquified before the solidification and then to convert it into fine-grained, solid form by spraying whereby only 1/3 of the heat of desublimation was drawn off, see Geiger German Patent No. 2,537,673 and related Geiger U.S. Pat. No. 4,038,276.
In this process the heat of melting is drawn off by inert gases brought into the separation container. By the use of the liquid cyanuric chloride chlorine and cyanogen chloride is removed before the solidification.
The precipitated solid cyanuric chloride was fine particled but the use of the inert gas as cooling medium required additional processing steps for discharging the cyanuric chloride from the inert gas.
The purpose of the invention is to provide a process for the recovery of cyanuric chloride in fine-grain (or fine particle) form with the aimed at narrow particle spectrum without large expense for apparatus.